Larry Livermore (founder of Lookout Records) was one-third of a recent panel talking about punk's history, present and future. He mentions Green Day a few times in the discussion talking about how they've made it to the mainstream from the punk scene.

The Ramones and Sex Pistols started out very anti-establishment, not intending to. Even though Green Day are multi-millionaires now, I don’t think it ruined their music, but it inspired a lot of clones. Making a lot of money affects the reality of music.

It's a pretty good read, if you're interested you can read the rest of it here.

Green Day was mentioned in Q's list of best award ceremony moments. They talk about Billie Joe walking up to a DJ at the end of an after party and asking him to play 'When I Come Around'. Apparently Billie Joe ended up being the only person to go out and dance on the floor, to his own music. They also mention that he was "very, very drunk". You can find the entire list here.